linux-stable.git/tools/perf/util/map.c, branch linux-5.2.y

perf unwind: Fix libunwind when tid != pid

2019-10-05T11:13:39+00:00

[ Upstream commit e8ba2906f6b9054102ad035ac9cafad9d4168589 ]

Commit e5adfc3e7e77 ("perf map: Synthesize maps only for thread group
leader") changed the recording side so that we no longer get mmap events
for threads other than the thread group leader (when synthesising these
events for threads which exist before perf is started).

When a file recorded after this change is loaded, the lack of mmap
records mean that unwinding is not set up for any other threads.

This can be seen in a simple record/report scenario:

	perf record --call-graph=dwarf -t $TID
	perf report

If $TID is a process ID then the report will show call graphs, but if
$TID is a secondary thread the output is as if --call-graph=none was
specified.

Following the rationale in that commit, move the libunwind fields into
struct map_groups and update the libunwind functions to take this
instead of the struct thread.  This is only required for
unwind__finish_access which must now be called from map_groups__delete
and the others are changed for symmetry.

Note that unwind__get_entries keeps the thread argument since it is
required for symbol lookup and the libdw unwind provider uses the thread
ID.

Signed-off-by: John Keeping 
Reviewed-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Konstantin Khlebnikov 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Fixes: e5adfc3e7e77 ("perf map: Synthesize maps only for thread group leader")
Link: http://lkml.kernel.org/r/20190815100146.28842-2-john@metanate.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf map: Fix potential NULL pointer dereference found by smatch tool

2019-07-31T05:24:49+00:00

[ Upstream commit 363bbaef63ffebcc745239fe80a953ebb5ac9ec9 ]

Based on the following report from Smatch, fix the potential NULL
pointer dereference check.

  tools/perf/util/map.c:479
  map__fprintf_srccode() error: we previously assumed 'state' could be
  null (see line 466)

  tools/perf/util/map.c
  465         /* Avoid redundant printing */
  466         if (state &&
  467             state->srcfile &&
  468             !strcmp(state->srcfile, srcfile) &&
  469             state->line == line) {
  470                 free(srcfile);
  471                 return 0;
  472         }
  473
  474         srccode = find_sourceline(srcfile, line, &len);
  475         if (!srccode)
  476                 goto out_free_line;
  477
  478         ret = fprintf(fp, "|%-8d %.*s", line, len, srccode);
  479         state->srcfile = srcfile;
              ^^^^^^^
  480         state->line = line;
              ^^^^^^^

This patch validates 'state' pointer before access its elements.

Signed-off-by: Leo Yan 
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexey Budankov 
Cc: Alexios Zavras 
Cc: Andi Kleen 
Cc: Changbin Du 
Cc: David S. Miller 
Cc: Davidlohr Bueso 
Cc: Eric Saint-Etienne 
Cc: Jin Yao 
Cc: Konstantin Khlebnikov 
Cc: Mathieu Poirier 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Rasmus Villemoes 
Cc: Song Liu 
Cc: Suzuki Poulouse 
Cc: Thomas Gleixner 
Cc: Thomas Richter 
Cc: linux-arm-kernel@lists.infradead.org
Fixes: dd2e18e9ac20 ("perf tools: Support 'srccode' output")
Link: http://lkml.kernel.org/r/20190702103420.27540-8-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf tools: Fix map reference counting

2019-04-17T17:30:11+00:00

By calling maps__insert() we assume to get 2 references on the map,
which we relese within maps__remove call.

However if there's already same map name, we currently don't bump the
reference and can crash, like:

  Program received signal SIGABRT, Aborted.
  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6

  (gdb) bt
  #0  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6
  #1  0x00007ffff75d0895 in abort () from /lib64/libc.so.6
  #2  0x00007ffff75d0769 in __assert_fail_base.cold () from /lib64/libc.so.6
  #3  0x00007ffff75de596 in __assert_fail () from /lib64/libc.so.6
  #4  0x00000000004fc006 in refcount_sub_and_test (i=1, r=0x1224e88) at tools/include/linux/refcount.h:131
  #5  refcount_dec_and_test (r=0x1224e88) at tools/include/linux/refcount.h:148
  #6  map__put (map=0x1224df0) at util/map.c:299
  #7  0x00000000004fdb95 in __maps__remove (map=0x1224df0, maps=0xb17d80) at util/map.c:953
  #8  maps__remove (maps=0xb17d80, map=0x1224df0) at util/map.c:959
  #9  0x00000000004f7d8a in map_groups__remove (map=, mg=) at util/map_groups.h:65
  #10 machine__process_ksymbol_unregister (sample=, event=0x7ffff7279670, machine=) at util/machine.c:728
  #11 machine__process_ksymbol (machine=, event=0x7ffff7279670, sample=) at util/machine.c:741
  #12 0x00000000004fffbb in perf_session__deliver_event (session=0xb11390, event=0x7ffff7279670, tool=0x7fffffffc7b0, file_offset=13936) at util/session.c:1362
  #13 0x00000000005039bb in do_flush (show_progress=false, oe=0xb17e80) at util/ordered-events.c:243
  #14 __ordered_events__flush (oe=0xb17e80, how=OE_FLUSH__ROUND, timestamp=) at util/ordered-events.c:322
  #15 0x00000000005005e4 in perf_session__process_user_event (session=session@entry=0xb11390, event=event@entry=0x7ffff72a4af8,
  ...

Add the map to the list and getting the reference event if we find the
map with same name.

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexei Starovoitov 
Cc: Andi Kleen 
Cc: Daniel Borkmann 
Cc: Eric Saint-Etienne 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Song Liu 
Fixes: 1e6285699b30 ("perf symbols: Fix slowness due to -ffunction-section")
Link: http://lkml.kernel.org/r/20190416160127.30203-10-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Check maps for bpf programs

2019-04-17T17:30:11+00:00

As reported by Jiri Olsa in:

  "[BUG] perf: intel_pt won't display kernel function"
  https://lore.kernel.org/lkml/20190403143738.GB32001@krava

Recent changes to support PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT
broke --kallsyms option. This is because it broke test __map__is_kmodule.

This patch fixes this by adding check for bpf program, so that these maps
are not mistaken as kernel modules.

Signed-off-by: Song Liu 
Reported-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexei Starovoitov 
Cc: Andi Kleen 
Cc: Andrii Nakryiko 
Cc: Daniel Borkmann 
Cc: Martin KaFai Lau 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Yonghong Song 
Link: http://lkml.kernel.org/r/20190416160127.30203-8-jolsa@kernel.org
Fixes: 76193a94522f ("perf, bpf: Introduce PERF_RECORD_KSYMBOL")
Signed-off-by: Jiri Olsa 
Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Purge all maps from the 'names' tree

2019-03-19T19:52:05+00:00

Add function __maps__purge_names() to purge all maps from the names
tree.  We need to cleanup the names tree in maps__exit().

Detected with gcc's ASan.

Signed-off-by: Changbin Du 
Reviewed-by: Jiri Olsa 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: Eric Saint-Etienne 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Steven Rostedt (VMware) 
Fixes: 1e6285699b30 ("perf symbols: Fix slowness due to -ffunction-section")
Link: http://lkml.kernel.org/r/20190316080556.3075-12-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf map: Remove map from 'names' tree in mapsremove()

2019-03-19T19:52:05+00:00

There are two trees for each map inserted by maps__insert(), so remove
it from the 'names' tree in __maps__remove().

Detected with gcc's ASan.

Signed-off-by: Changbin Du 
Reviewed-by: Jiri Olsa 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: Eric Saint-Etienne 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Steven Rostedt (VMware) 
Fixes: 1e6285699b30 ("perf symbols: Fix slowness due to -ffunction-section")
Link: http://lkml.kernel.org/r/20190316080556.3075-11-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf map: Move structs and prototypes for map groups to a separate header

2019-02-06T13:00:38+00:00

And since machine.h only needs what is in there, make it stop including
map.h and instead include this newly introduced map_groups.h instead.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-dbob25fv5rp2rjpwlnterf38@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Use cached rbtrees

2019-01-25T14:12:10+00:00

At the cost of an extra pointer, we can avoid the O(logN) cost of
finding the first element in the tree (smallest node).

Signed-off-by: Davidlohr Bueso 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: http://lkml.kernel.org/r/20181206191819.30182-6-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Support 'srccode' output

2018-12-17T17:57:07+00:00

When looking at PT or brstackinsn traces with 'perf script' it can be
very useful to see the source code. This adds a simple facility to print
them with 'perf script', if the information is available through dwarf

  % perf record ...
  % perf script -F insn,ip,sym,srccode
  ...

            4004c6 main
  5               for (i = 0; i < 10000000; i++)
             4004cd main
  5               for (i = 0; i < 10000000; i++)
             4004c6 main
  5               for (i = 0; i < 10000000; i++)
             4004cd main
  5               for (i = 0; i < 10000000; i++)
             4004cd main
  5               for (i = 0; i < 10000000; i++)
             4004cd main
  5               for (i = 0; i < 10000000; i++)
             4004cd main
  5               for (i = 0; i < 10000000; i++)
             4004cd main
  5               for (i = 0; i < 10000000; i++)
             4004b3 main
  6                       v++;

  % perf record -b ...
  % perf script -F insn,ip,sym,srccode,brstackinsn

  ...
         main+22:
          0000000000400543        insn: e8 ca ff ff ff            # PRED
  |18                     f1();
          f1:
          0000000000400512        insn: 55
  |10       {
          0000000000400513        insn: 48 89 e5
          0000000000400516        insn: b8 00 00 00 00
  |11             f2();
          000000000040051b        insn: e8 d6 ff ff ff            # PRED
          f2:
          00000000004004f6        insn: 55
  |5        {
          00000000004004f7        insn: 48 89 e5
          00000000004004fa        insn: 8b 05 2c 0b 20 00
  |6              c = a / b;
          0000000000400500        insn: 8b 0d 2a 0b 20 00
          0000000000400506        insn: 99
          0000000000400507        insn: f7 f9
          0000000000400509        insn: 89 05 29 0b 20 00
          000000000040050f        insn: 90
  |7        }
          0000000000400510        insn: 5d
          0000000000400511        insn: c3                        # PRED
          f1+14:
          0000000000400520        insn: b8 00 00 00 00
  |12             f2();
          0000000000400525        insn: e8 cc ff ff ff            # PRED
          f2:
          00000000004004f6        insn: 55
  |5        {
          00000000004004f7        insn: 48 89 e5
          00000000004004fa        insn: 8b 05 2c 0b 20 00
  |6              c = a / b;

Not supported for callchains currently, would need some layout changes
there.

Committer notes:

Fixed the build on Alpine Linux (3.4 .. 3.8) by addressing this
warning:

  In file included from util/srccode.c:19:0:
  /usr/include/sys/fcntl.h:1:2: error: #warning redirecting incorrect #include  to  [-Werror=cpp]
   #warning redirecting incorrect #include  to 
    ^~~~~~~
  cc1: all warnings being treated as errors

Signed-off-by: Andi Kleen 
Tested-by: Jiri Olsa 
Link: http://lkml.kernel.org/r/20181204001848.24769-1-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo

perf map: Remove extra indirection from map__find()

2018-12-17T17:53:57+00:00

A double pointer is used in map__find() where a single pointer is enough
because the function doesn't affect the rbtree and the rbtree is locked.

Signed-off-by: Eric Saint-Etienne 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Eric Saint-Etienne 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1542969759-24346-1-git-send-email-eric.saint.etienne@oracle.com
Signed-off-by: Arnaldo Carvalho de Melo